I was looking for a rescue system...
It has to boot via pxe, just in case that all harddisk are down on my server(s).
Some days ago I wrote a similar howto: http://www.sysresccd.org/forums/viewtopic.php?t=1157
The downside of the system rescue CD is, that I did not found a howto, how to customise the installed packages (remove and add).

These steps arn't required. But you have to take care! Please ajust the all scripts; they have to fit to your locations! In this howto, most scripts are executet to/from /opt/gnap!
This howto is a hack. It works for me. Follow on your own risk!

3. copy needed files from the iso
copy the kernel to the tftproot. On my system its under /tftproot. All gnap relatet tftp boot files are under /tftproot/gnap.
My working directory for gnap is /opt/gnap.